The present invention relates to a flow control apparatus that allows fluid to flow through a valve under a first set of conditions and which prevents fluid from flowing through the valve under a second set of conditions. The invention is particularly well suited for use with outside water spigots and hoses to ensure that water flows when the temperature of the water and/or the surrounding air is at or close to the freezing temperature of water to prevent pipes and hoses from bursting as a result of water freezing and expanding therein.
During winter months when the air temperature drops below freezing (32xc2x0 F.), water pipes and hoses may burst as a result of water within them freezing and expanding. It is common to allow water to flow through these conduits in order to prevent the water from freezing. Another alternative is to purge the conduits of water prior to the temperature dropping below freezing in order to ensure that they do not fracture in the event that the temperature drops below freezing.
Various types of devices have been developed that automatically enable water to flow through conduits when the air temperature drops below a certain temperature in order to prevent the conduits from bursting. However, these devices typically are relatively complicated and are comprised of many moving parts. Consequently, the devices are more likely to malfunction and thus require replacement or repair.
Accordingly, a need exists for a flow control apparatus that is reliable, less likely to malfunction than prior devices that perform the same function and that is relatively simple in design and inexpensive to manufacture.
The present invention provides a flow control apparatus and method. In accordance with the present invention, the flow control apparatus comprises a thermostat that automatically actuates valve to enable water to flow through the valve when the temperature of the air or water is at or near the freezing temperature of water (32xc2x0 F.). When the temperature of the air and/or water rises above freezing, the thermostat causes the valve to close, thereby preventing water from flowing through the valve. Therefore, when the apparatus is coupled to an end of a water conduit, such as a water spigot or hose, water is allowed to flow through the conduit when the air and/or water temperature is at or near freezing to prevent the conduit from bursting due to water freezing and expanding within the conduit.
In accordance with the preferred embodiment of the present invention, the thermostat measures the temperature of the water flowing through the conduit and actuates the valve accordingly. In other words, when the temperature of the water flowing through the conduit drops below a particular temperature, the thermostat causes the valve to open, whereas when the temperature of the water flowing through the conduit rises above a particular temperature, the thermostat causes the valve to close. When the valve is open water is allowed to flow through the conduit, whereas when the valve is closed, water is not allowed to flow through the conduit.
In accordance with an alternative embodiment of the present invention, the thermostat measures the temperature of the air surrounding a portion of the conduit and actuates the valve accordingly. In other words, when the temperature of the air drops below a particular temperature, the thermostat causes the valve to open, whereas when the temperature of the air rises above a particular temperature, the thermostat causes the valve to close. When the valve is open water is allowed to flow through the conduit, whereas when the valve is closed, water is not allowed to flow through the conduit.
The apparatus of the present invention can be designed in several ways with several different thermostat/valve and housing designs. Preferably, the thermostat is comprised of a bi-metal strip that flexes in a direction away from the valve when the temperature of water surrounding the strip drops below a particular temperature. In accordance with this embodiment, the strip abuts an opening in the housing of the apparatus when the temperature of the water is above a certain temperature, which seals the opening and prevents water from flowing through it. Conversely, when the temperature of the water drops below a certain temperature, the strip flexes away from the opening, thereby allowing water to flow through the opening and out of the apparatus housing.
These and other features of the present invention will become apparent from the following description, drawings and claims.